CORVALLIS — Markus Wheaton takes a little offense to the description of him being “flimsy” last year but let’s face it, the 6-foot-1, 182-pound receiver isn’t exactly built like a tank.

Wheaton only put on a few pounds in the offseason, but it was his work ethic in the summer — combined with a slight increase in weight — that’s caught Mike Riley’s attention.

“(Receivers) were the best working group from our whole team in the summer, and Wheaton and (Brandin) Cooks were the leaders.” Riley said.

But their work went beyond the weight room. Wheaton put himself through his own version of daily doubles with cornerback Jordan Poyer, often going one-on-one at night after team workouts in the morning.

Their motivation was simple: A dismal 3-9 season still stings.

“It was everything,” Wheaton said. “It was about last year. Our last season (as seniors). Our numbers. Everything that goes into football was a part of it. And I think it’s made a difference.”

Now a veteran, Wheaton’s also taking young guys under his wing when possible. On Friday, when sophomore receiver Obum Gwacham got confused on a play call, it was Wheaton who went over, pulled Gwacham aside and explained how to do things correctly.

“Young guys want to learn, want to get in, want to contribute and I think that’s the most important thing,” Wheaton said. “I’ve been there. I’ve got the little things down and all the basics, so when a guy messes up, I can be there to help him out.”

It’s hard to tell how much difference Wheaton’s slightly beefed up frame will make because Oregon State hasn’t done any live tackling yet. But Poyer is convinced all their work will be obvious come Sept. 1. Along with additional individual workouts, Poyer said players orchestrated a 7-on-7 game with Western Oregon, anxious for extra reps as a team.

So does this mean that daily doubles won’t be as big of a shock to the systems of Wheaton and Poyer when they start Saturday?

“We’ve been out of it (doubles) for a week because of this practice,” he said. “Who knows what tomorrow will bring?”

Mannion a leader, too: Wheaton isn’t the only player whose offseason leadership made an impact.

Riley has raved since Pac-12 media day about the jump quarterback Sean Mannion has made, repeatedly pointing out that the Beavers have never elected a sophomore team captain. That’s a distinction that Mannion holds this year.

Mannion, who moved to the No. 1 spot last year after upperclassman Ryan Katz was benched, has emerged in fall camp with a little more confidence. Teammates say is he more talkative, and has actively taken on more of a vocal leadership role, a must for his position.

But don’t count on him getting cocky anytime soon. Asked if he senses a growing confidence and swagger throughout the team — a characteristic the Beavers sorely lacked last season — Mannion laughed.

“I don’t know if I’m the best person to talk about swagger,” he said. “I keep a pretty low profile. But the attitude around here has definitely changed. There’s a confidence that everyone has that we know we can be good. We know it’s a challenge, but we’re up to it.”